1 /*
2 * Copyright (C) 2009 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 #ifndef DATA_SOURCE_H_
18
19 #define DATA_SOURCE_H_
20
21 #include <sys/types.h>
22 #include <media/stagefright/foundation/ADebug.h>
23 #include <media/stagefright/MediaErrors.h>
24 #include <utils/Errors.h>
25 #include <utils/KeyedVector.h>
26 #include <utils/List.h>
27 #include <utils/RefBase.h>
28 #include <utils/threads.h>
29 #include <drm/DrmManagerClient.h>
30
31 namespace android {
32
33 struct AMessage;
34 struct AString;
35 class IDataSource;
36 struct IMediaHTTPService;
37 class String8;
38 struct HTTPBase;
39
40 class DataSource : public RefBase {
41 public:
42 enum Flags {
43 kWantsPrefetching = 1,
44 kStreamedFromLocalHost = 2,
45 kIsCachingDataSource = 4,
46 kIsHTTPBasedSource = 8,
47 };
48
49 static sp<DataSource> CreateFromURI(
50 const sp<IMediaHTTPService> &httpService,
51 const char *uri,
52 const KeyedVector<String8, String8> *headers = NULL,
53 String8 *contentType = NULL,
54 HTTPBase *httpSource = NULL);
55
56 static sp<DataSource> CreateMediaHTTP(const sp<IMediaHTTPService> &httpService);
57 static sp<DataSource> CreateFromIDataSource(const sp<IDataSource> &source);
58
DataSource()59 DataSource() {}
60
61 virtual status_t initCheck() const = 0;
62
63 // Returns the number of bytes read, or -1 on failure. It's not an error if
64 // this returns zero; it just means the given offset is equal to, or
65 // beyond, the end of the source.
66 virtual ssize_t readAt(off64_t offset, void *data, size_t size) = 0;
67
68 // Convenience methods:
69 bool getUInt16(off64_t offset, uint16_t *x);
70 bool getUInt24(off64_t offset, uint32_t *x); // 3 byte int, returned as a 32-bit int
71 bool getUInt32(off64_t offset, uint32_t *x);
72 bool getUInt64(off64_t offset, uint64_t *x);
73
74 // Reads in "count" entries of type T into vector *x.
75 // Returns true if "count" entries can be read.
76 // If fewer than "count" entries can be read, return false. In this case,
77 // the output vector *x will still have those entries that were read. Call
78 // x->size() to obtain the number of entries read.
79 // The optional parameter chunkSize specifies how many entries should be
80 // read from the data source at one time into a temporary buffer. Increasing
81 // chunkSize can improve the performance at the cost of extra memory usage.
82 // The default value for chunkSize is set to read at least 4k bytes at a
83 // time, depending on sizeof(T).
84 template <typename T>
85 bool getVector(off64_t offset, Vector<T>* x, size_t count,
86 size_t chunkSize = (4095 / sizeof(T)) + 1);
87
88 // May return ERROR_UNSUPPORTED.
89 virtual status_t getSize(off64_t *size);
90
flags()91 virtual uint32_t flags() {
92 return 0;
93 }
94
toString()95 virtual String8 toString() {
96 return String8("<unspecified>");
97 }
98
reconnectAtOffset(off64_t offset)99 virtual status_t reconnectAtOffset(off64_t offset) {
100 return ERROR_UNSUPPORTED;
101 }
102
103 ////////////////////////////////////////////////////////////////////////////
104
105 bool sniff(String8 *mimeType, float *confidence, sp<AMessage> *meta);
106
107 // The sniffer can optionally fill in "meta" with an AMessage containing
108 // a dictionary of values that helps the corresponding extractor initialize
109 // its state without duplicating effort already exerted by the sniffer.
110 typedef bool (*SnifferFunc)(
111 const sp<DataSource> &source, String8 *mimeType,
112 float *confidence, sp<AMessage> *meta);
113
114 static void RegisterDefaultSniffers();
115
116 // for DRM
117 virtual sp<DecryptHandle> DrmInitialization(const char *mime = NULL) {
118 return NULL;
119 }
getDrmInfo(sp<DecryptHandle> & handle,DrmManagerClient ** client)120 virtual void getDrmInfo(sp<DecryptHandle> &handle, DrmManagerClient **client) {};
121
getUri()122 virtual String8 getUri() {
123 return String8();
124 }
125
126 virtual String8 getMIMEType() const;
127
close()128 virtual void close() {};
129
130 protected:
~DataSource()131 virtual ~DataSource() {}
132
133 private:
134 static Mutex gSnifferMutex;
135 static List<SnifferFunc> gSniffers;
136 static bool gSniffersRegistered;
137
138 static void RegisterSniffer_l(SnifferFunc func);
139
140 DataSource(const DataSource &);
141 DataSource &operator=(const DataSource &);
142 };
143
144 template <typename T>
getVector(off64_t offset,Vector<T> * x,size_t count,size_t chunkSize)145 bool DataSource::getVector(off64_t offset, Vector<T>* x, size_t count,
146 size_t chunkSize)
147 {
148 x->clear();
149 if (chunkSize == 0) {
150 return false;
151 }
152 if (count == 0) {
153 return true;
154 }
155
156 T tmp[chunkSize];
157 ssize_t numBytesRead;
158 size_t numBytesPerChunk = chunkSize * sizeof(T);
159 size_t i;
160
161 for (i = 0; i + chunkSize < count; i += chunkSize) {
162 // This loops is executed when more than chunkSize records need to be
163 // read.
164 numBytesRead = this->readAt(offset, (void*)&tmp, numBytesPerChunk);
165 if (numBytesRead == -1) { // If readAt() returns -1, there is an error.
166 return false;
167 }
168 if (numBytesRead < numBytesPerChunk) {
169 // This case is triggered when the stream ends before the whole
170 // chunk is read.
171 x->appendArray(tmp, (size_t)numBytesRead / sizeof(T));
172 return false;
173 }
174 x->appendArray(tmp, chunkSize);
175 offset += numBytesPerChunk;
176 }
177
178 // There are (count - i) more records to read.
179 // Right now, (count - i) <= chunkSize.
180 // We do the same thing as above, but with chunkSize replaced by count - i.
181 numBytesRead = this->readAt(offset, (void*)&tmp, (count - i) * sizeof(T));
182 if (numBytesRead == -1) {
183 return false;
184 }
185 x->appendArray(tmp, (size_t)numBytesRead / sizeof(T));
186 return x->size() == count;
187 }
188
189 } // namespace android
190
191 #endif // DATA_SOURCE_H_
192